JP4988188B2 - Chair with backrest - Google Patents

Description

  The present invention relates to a chair having a backrest.

  The chair has various forms and structures. For example, in a swivel chair often used for office work, the seat is supported by a seat support base attached to a leg column, and the seat support base is against the spring means. In many cases, a tilting back support frame is attached, and a backrest is attached to a back column provided on the back support frame.

Although the structure of the backrest is also various, as an example, the applicant of the present application in Patent Document 1 made the entire backrest made of synthetic resin and inserted the lower part of the backrest into the back column of the back support frame, and by using a stopper made of a metal plate. Disclosed is a configuration that prevents the upward movement of the backrest.
JP 2005-21467 A

The biggest problem in carrying and storing chairs is that they are bulky for their density. Therefore, with the configuration can be easily assembled and are separated into several parts, can suppress the cost of handling in storage and distribution stage, also, there is an advantage that the manufacturing knockdown method can be adopted easily. In particular, in the case of a high-back specification with a high backrest, the merit is demonstrated more strongly.

  According to the configuration disclosed in the prior application, since the backrest can be easily attached, the cost and labor required for storage, transportation, and assembly can be reduced.

  It is an object of the present invention to further improve the ease of attaching a backrest by further developing the configuration disclosed in this prior application.

  The chair of the present invention includes a seat, a backrest having a main support having a strength to support a backrest load of a seated person, and a backrest unit to which the backrest is attached, and the main support of the backrest and the backrest unit. In addition, there is provided attachment means that fits each other by moving the main support from substantially upward to downward or substantially from the rear to the front, and holds both of them so that they cannot move relative to each other. A male fitting portion that includes at least two types of fitting means, that is, a first fitting means and a second fitting means, and these fitting means are relatively immovable in the front-rear direction when they are fitted to each other. And a female fitting part.

Further, the first fitting means and the second engagement means and is provided by shifting the vertical position and the right position to each other, the male engaging portion and the female engaging portion in the first fitting means And the fitting length of the male fitting portion and the female fitting portion of the second fitting means are longer than the fitting length of the male fitting portion of the first fitting means, When the main support is moved in a state where the female fitting portion is fitted, the male fitting portion and the female fitting portion of the second fitting means are set to fit with each other.

Then, the back receiving unit is attached to the seat receiving base to the rear tilt against the battlefield it means, on the back rest unit, a male fitting portion of the first fitting means left While the pair of support columns are arranged in a state of being distributed to the left and right in a front view, the main support is formed in a shell shape with a synthetic resin, and the first fitting is disposed at a lower end portion of the main support. As a female fitting portion of the coupling means, a downward opening mounting hole into which the post portion is fitted is formed.

Furthermore, the separate component position below the lower end of the mounting holes of the front portion of the main support, as female engaging portion of the second fitting means, are formed sandwiching portion which opens downward in side view cage, the said back rest unit, as male engaging portion of the second fitting means, a horizontal axis portion fitted from above is provided by the deformation of the clamping part against the elastic.

The invention according to claim 2 in which the ingredients embody claim 1, in the present invention, the spring means is a compression coil spring, the back receiving unit includes a case of substantially downwardly opening covering said coil spring cage, wherein the rear horizontal shaft portion of the case are the strut is bent formed at the tip protrudes to the left and right, to the strut, pin-like synthetic resin which is fitted inside the mounting hole while the protection member is attached to the lower end portion and the front portion of the main support, as the engaging means for holding the receiving back the main support unit in a state where no upward motion from below the rear lower end edge of the case A hooking step is formed, and when the first fitting means and the second fitting means are fitted to each other, the step is pulled from below to the rear lower edge of the case by elastic deformation of the main support. It is set to take.

  According to the present invention, the backrest is moved in a fixed direction so that the male fitting portion and the female fitting portion of the two types of fitting means, the first fitting means and the second fitting means, are fitted to each other. Thus, the backrest is held in a state where it does not move back and forth relative to the backrest unit (in the case of a rocking chair, the backrest unit and the backrest are tilted backward together).

  In this case, since the fitting direction of the male fitting portion and the female fitting portion is the same in the first fitting means and the second fitting means, the backrest is simply in one direction such as downward. For this reason, the installation work is easy and easy to install. Moreover, since the first fitting means and the second fitting means are separated from each other vertically and horizontally with the backrest attached to the backrest unit, the backrest load caused by the seated person leaning against the backrest It is possible to prevent the (moment) from concentrating on a specific location and to secure a high support strength.

  Therefore, according to the present invention, it is possible to improve the efficiency and reliability of the mounting operation of the backrest (and thus the assembly operation of the chair) while securing the mounting strength of the backrest.

Back In this case, the provision of the Mi knob for hardness adjustment of the spring means, it is possible to undetachable holding the back rest unit backrest using the hardness adjusting hysterectomy Mami spring means, for example, to pull the backrest upwards There will be no detachment from the receiving unit.

According to the second aspect of the present invention, it is possible to further prevent stress from concentrating on a narrow portion of the main support in the backrest by the buffering action of the resin protective member constituting the back column. Due to the presence of the engaging means comprising the case, there is an advantage that the backrest can be prevented from rattling without providing fixing means such as screws.

(1). Outline of Chair Next, an embodiment of the present invention will be described with reference to the drawings. The present invention is applied to a swivel chair frequently used for office work. First, an outline will be described based on FIGS. FIG. 1 is a front view of a chair, FIG. 2A is a plan view seen from behind, FIG. 1B is a left side view, and FIG. 3A is an outer shell (main support) that constitutes a backrest. FIG. 4 is a perspective view from the front, FIG. 4B is a partial perspective view of the outer shell as viewed from the rear, FIG. 4 is an exploded perspective view of the member, and FIG.

  The chair includes a leg 1, a seat 2, a backrest 3, and an armrest device 4 (the armrest device 4 has a pair of left and right, but only one of them is shown in the figure). The leg 1 includes a leg column 5 made of a gas cylinder and a plurality (five) of branch legs extending radially, and a caster is provided at the tip of each branch leg 6.

  A seat receiving base 6 that opens upward is attached to the upper end of the leg support 5. A seat receiving shell 7 is attached to the upper surface of the seat receiving base 6, and the seat 2 is attached to the seat receiving shell 7. Installed. From the left side surface of the seat support base 6, a lock lever 8 for switching the backrest 3 between a state in which the backrest 3 can be tilted backward and a state in which the backrest 3 cannot be tilted is exposed. The elevating lever 9 for adjusting the height 2 is exposed. The lifting lever 9 extends in the left-right direction along the lower surface of the front portion of the seat 2.

  The backrest 3 includes an outer shell 10 made of synthetic resin as an example of a main support. The outer shell 10 is formed in a form in which a back rest 10a that supports the back of a seated person and a waist rest 10b that supports the waist of the seated person are vertically connected. 1 has a lower part 10c extending downward from 1, and this lower part 10c controls the mounting function. As shown in FIG. 3, the lower portion 10 c of the outer shell 10 is formed in a rounded mountain shape with a downward convexity when viewed from the front. Cushion bodies 11 and 12 are mounted on the front surfaces of the back pad 10a and the waist pad 10b, respectively.

  For example, as shown in FIG. 3, the backrest portion 10a of the backrest 3 is formed in a substantially inverted trapezoidal shape with the uppermost portion being the widest and the width being reduced downward, while the waistrest portion 10b is substantially in a front view. For this reason, the boundary between the back pad 10a and the waist pad 10b has a narrow profile with a smooth curve in front view.

  In addition, as can be understood from FIG. 2A, the left and right side portions of the waist rest portion 10b are formed in a chevron shape that protrudes forward from the back rest portion 10a and is convex forward in a side view. The left and right side portions of the portion 10b are thick portions 10d that are much thicker than other portions. The thick part 10d extends to a part of the lower part 10c.

  A back support unit 13 shown in FIG. 4 is attached to the seat support base 6 so as to be able to tilt backward, and the outer shell 10 of the backrest 3 is attached to the back support unit 13, and the back support unit 13 is a spring. The unit 14 is elastically supported. The spring unit 14 is covered with a cover 15 from below. Hereinafter, the mounting structure of the backrest 3 will be described with reference to FIG.

(2). Mounting structure of the backrest FIG. 7 is a separated front view of the backrest unit 13 and the backrest 3, FIG. 8 is a partially broken front view of the backrest unit 13 with the backrest 3 attached, and FIG. VIIIA-VIIIA view, FIG. 9 is a bottom view of the backrest 3, FIG. 10A is a sectional view taken along the line XA-XA in FIG. 8, and FIG. 9B is a sectional view taken along the line BB in FIG. (A) is a cross-sectional view in the middle of attaching the backrest as viewed from the XIA-XIA view of FIG. 7, (B) (C) is a cross-sectional view of the XIB-XIB view of FIG. 8 with the backrest attached. XIC-XIC sectional view, (D) is a rear view of the back support unit 13.

  The seat receiving base 6 of the present embodiment is a metal or resin molded product such as aluminum die casting (of course, a sheet metal product may be used). The seat 2 has a structure in which a cushion is stretched on a shell-like seat plate made of a synthetic resin, and although the details are omitted, the seat plate is detachably attached to the seat receiving shell 9.

  As shown in FIGS. 4 and 5, the back support unit 13 includes a frame body 16 having a substantially U shape in plan view formed by bending a metal round bar, and a block shape fixed to the rear end portion of the frame body 16 by welding. The case (housing) 17 and a pair of left and right metal round bar members 18 fixed to the case 17 by being inserted from the side are provided. The frame body 16 has its rear end inserted into the case 17 and fixed with screws. The frame body 16 and the rod member 18 may be made of a pipe, and the cross-sectional shape thereof may be a square or the like.

Case 17 is for example a molded article such as a die-cast aluminum (or resin products and sheet metal products), as can be inferred from FIG. 6 For example, downward and a rear surface portion and the upper surface portion and the right and left side portions It has an open form. Case 17 may consist of a plurality of members.

  A left and right front end of the frame body 16 in the back support unit 13 is a rotating shaft 16a, and the rotating shaft 16a is rotatably attached to the seat receiving base 6. Specifically, as shown in FIGS. 5 and 6, a lower bearing 19 that overlaps the rotating shaft 16 a from below and an upper bearing 20 that overlaps from above are disposed inside the seat receiving base 6 so as to overlap both bearings. 19 and 20 are held by the pressing member 21 so as not to be detached.

The pressing member 21 is fixed to the upper surface of the boss portion 22 formed on the seat receiving base 6 with screws 23. The upper and lower bearings 19 and 20 are fitted to each other so as not to come off. Further, in the present embodiment, the lower bearing 19 is also provided with stop and bearing functions omission of lifting lever 9.

  As schematically shown in FIG. 4, a resin guide member 24 in which the left and right sides are formed vertically is inserted and attached to the rear portion of the seat receiving base 6. The back support unit 13 is held by the guide member 24 so that it cannot be displaced left and right. Further, as shown in FIG. 6, the frame body 16 of the back receiving unit 13 is prevented from turning upward by a left and right long metal stay 25 fastened to the seat receiving base 6 by screws.

  As shown in FIGS. 4 and 6, a pair of left and right stoppers 26 positioned inside the seat receiving base 6 are attached to the lock lever 8 so as not to be relatively rotatable. The stopper 26 is located below the longitudinal longitudinal portion of the frame body 16 in the back support unit 13, and by rotating the lock lever 8 to change the stopper 26 between a standing posture and a laterally tilted posture, Switching between the backward tiltable state and the backward tiltable state FIG. 6 shows a locked state that cannot be rotated.

  Although not described in detail, a receiving member 27 is disposed below the left and right stoppers 26 so as not to be displaced at the bottom of the seat receiving base 6. The receiving member 27 is provided with an engaging portion 27a that is elastically deformed and fits in and out of the stopper 26, and the stopper 26 is held in a locked posture by the action of the engaging portion 27a. Since the lock mechanism is specially devised, it will be described later.

As shown in FIGS. 4 and 7, the bar member 18 of the back support unit 13 is made of a metal round bar, and has a horizontal shaft portion 18a extending in the left-right direction and a column portion rising upward from the tip thereof via an inclined portion 18b. 18c, and the column portion 18c extends to the thick portion 10d of the outer shell 10. A protective member 28 made of synthetic resin is fitted into the support column 18c so as not to be removed by forcible fitting or screwing. As shown in FIGS. 8 and 7, the protective member 28 is thicker than the outer shell 10. The fitting hole 29 of the downward opening formed in the part 10d is fitted from below.

In the present embodiment, the support column 18 c having the protection member 28 and the attachment hole 29 constitute the first fitting means described in claim 1. Note that the protection member 28 is not necessarily required, and the first fitting means may be configured by the column portion 18 c of the rod member 18 and the attachment hole 29.

The protective member 28 includes a straight tube 28a that fits in the support column 18c, and a small-diameter, tapered and tapered shaft portion 28b that is integrally formed at the upper end thereof. Are formed integrally, and a circumscribed circle in contact with the straight tube portion 28a and the group of the annular protrusions 28c is tapered as a whole. The tip of the small diameter shaft portion 28a (or the annular protrusion 28c at the tip) is rounded. On the other hand, the mounting hole 29 of the outer shell 10 also has a straight portion 29 a and a tapered portion 29 b corresponding to the shape of the protective member 28.

In the neutral state where the person does not lean on the backrest 3, the support column 18c and the protection member 28 of the left and right bar members 18 extend in parallel in the vertical direction in the front view and overlap in the vertical direction in the side view. It extends. Therefore, when the outer shell 10 is fitted downward into the protective member 28, the outer shell 10 is guided by the straight tube portion 28 a of the protective member 28 and moves directly below.

The vertical fitting length between the straight tube portion 28 a of the protection member 28 and the straight portion 29 a of the attachment hole 29 is larger than the outer diameter of the rod member 18 in the back support unit 13.

  As shown in FIG. 10A, escape holes 30 that open downward are formed on both the left and right sides of the thick portion 10d of the outer shell 10 across the mounting hole 29 in plan view. This is to suppress the occurrence of sink marks or uneven stress in the thick portion 18d during molding.

  For example, as shown in FIGS. 3, 7, 8, and 11, a laterally long rib 32 is provided on the lower front surface of the outer shell 10 so as to extend left and right above the lower end edge. Thus, a sandwiching portion 33 having a downward opening in side view and fitted into the horizontal shaft portion 18a of the bar member 18 in the back support unit 13 from above is integrally formed. The gap between the opening edges of the sandwiching portion 33 is slightly smaller than the outer diameter of the rod member 18, and therefore the sandwiching portion 33 is fitted to the horizontal shaft portion 18a of the rod member 18 by its own elastic deformation. (Engage). In the present embodiment, the clamping portion 33 and the horizontal shaft portion 18 constitute the second fitting means described in claim 1.

Of the peripheral edge of the lower part of the outer shell 10, a portion between the both ends of the horizontally long rib 32 and the attachment hole 29 has a groove shape that fits into the inclined portion 18 b of the rod member 18 from above, and this groove portion Is indicated by reference numeral 34 in FIGS. Due to the presence of the groove-shaped portion 34, the functions of the outer shell 10 and the rod member 18 of the back support unit 13 and the positioning are improved.

  For example, as shown in FIGS. 3, 6, and 7, a circular through hole 35 located in the left and right intermediate portion of the outer shell 10 is vacant below the horizontally long rib 32 in the lower end portion of the outer shell 10, On both sides of the through-hole 35, a box-shaped and vertically long engaging portion 36 made of a rib group is provided so as to protrude from the back portion of the engaging portion 36 as shown in FIG. A lower end edge 17a of the rear portion of the case 17 in the unit 13 forms a step portion 36a on which the unit 13 is mounted from above. The rear surface of the case 17 overlaps the front surface of the engaging portion 36.

  In the neutral state where the person does not lean on the backrest 3, the inclined portion 18b of the bar member 18, the rear surface of the case 17, and the front surface of the engaging portion 36 in the back support unit 13 are inclined forward at the same angle in a side view. .

In attaching the outer shell 10 to the back support unit 13, the left and right attachment holes 29 may be fitted into the left and right protection members 28 in the back support unit 13 and pressed down downward. In early this fitting, by on the protective member 28 is tapered, guiding been conducted of mounting holes 29 for protection member 28, Mari mounting hole 29 is fitted to smoothly tapered portion 28a of the protection member 28 Include.

And since the fitting length of the straight cylinder part 28a of the protection member 28 and the straight part 29a of the attachment hole 29 is larger than the outer diameter dimension of the rod member 18 in the back support unit 13, the outer shell 10 is accurately The holding portion 33 is fitted into the horizontal shaft portion 18 a of the bar member 18 by moving downward while maintaining the posture.

  Then, at the final stage when the sandwiching portion 33 of the outer shell 10 is fitted into the rod member 18, the rear lower end edge 17 a of the case 17 engages with (hangs on) the stepped portion 36 a of the engaging portion 36 due to elastic deformation of the outer shell 10. ). As a result, the outer shell 10 is attached to the back support unit 13.

  In addition, since the outer shell 10 moves vertically downward, the engaging portion 36 of the outer shell 10 and the rear surface of the case 17 are inclined forward, so that the horizontal shaft portion 18a of the bar member 18 is held by the clamping portion 33. The lower end edge of the rear portion of the case 17 hits the front end of the step portion 36a in the engaging portion 36 after being fitted into the engagement portion 36. Therefore, the presence of the step portion 36a impairs the fitting between the holding portion 33 and the horizontal shaft portion 18a. It will never be.

When a seated person leans against the backrest 3, an external force is applied to the protective member 28 attached to the column portion 18 c of the bar member 18, but in the present embodiment, the protective member 28 has three steps with the straight portion 28 a. Since the contact with the mounting hole 29 of the outer shell 10 is made at four locations with the annular projection 28c, stress can be prevented from concentrating on a specific part of the mounting hole 29, and the support strength (durability) against the back load can be improved. There are advantages. Further, the protective member 28 is made of synthetic resin and is somewhat elastically deformed (that is, buffering) also suppresses stress concentration.

  When the seated person leans against the backrest 3, a moment is generated in the outer shell 10 to tilt backward about the rear lower end edge 17 a of the case 17, but the clamping part 33 has a rear lower end edge 17 a of the case 17. Since the moment acting on the clamping part 33 is small, the clamping part 33 is not broken. Further, since the back load acts so as to bring the engaging portion 36 of the outer shell 10 into close contact with the case 17, there is no inconvenience that the stepped portion 36a is detached from the case 17 due to the back load.

  A downward projection 17b is formed in the left and right middle portion of the lower end edge of the rear portion of the case 17 constituting the back support unit 13, while a hole 37 that fits into the projection 17b is formed in the cover 15. (See FIGS. 6, 11, and 4).

(3). Spring Unit Next, the spring unit 14 will be described mainly based on FIGS. 4 and 6. The spring unit 14 includes a compression coil spring 40 as an example of a spring body, a front spring receiver 41 that receives the compression coil spring 40 from the front, a rear spring receiver 42 that receives the compression coil spring 40 from the rear, and a front and rear spring receiver. An adjustment rod (adjustment bolt) 43 fitted to 41, 42, a hardness adjustment knob (may be referred to as a handle or a lever) 44 fitted to the adjustment rod 43 from the rear, and a front spring receiver 41 And a shaft support member 45 fitted from the front side.

  The shaft support member 45 is supported by the rear end portion of the seat receiving base 6 via a receiving member 46 made of synthetic resin. Since the contact surface between the shaft support member 45 and the receiving member 46 is formed in an arc shape in the side cross section, the rotation of the shaft support member 45 is allowed and is held so that it cannot be detached vertically. Although not shown, the fitting portion between the shaft support member 45 and the front spring receiver 41 has a square cross section (non-circular), and therefore the front spring receiver 41 is held non-rotatable, and The front spring receiver 41 is fitted to the shaft support member 45 so as to slide forward and backward.

  On the other hand, the rear spring receiver 42 enters the space of the case 17 in the back support unit 13. In addition, a cylindrical boss portion 42 a into which the adjustment rod 43 is fitted protrudes rearward from the rear spring receiver 42, and the boss portion 42 a is exposed rearward from a hole provided in the case 17.

  A nut 47 is embedded in the front spring receiver 41 so as not to rotate, and an adjustment rod 43 is screwed into the nut 47. A spacer 48 is fitted to the front end portion of the adjustment rod 43, and the spacer 48 is housed in the shaft support member 45. A washer is fixed to the front end surface of the adjustment rod 43 with a screw 49.

  A non-circular head 43a such as a hexagon is integrally provided at the rear end of the adjusting rod 43, and a boss portion 44a of a hardness adjusting knob 44 is fitted into the head 43a. The fitting of the hardness adjusting knob 44 to the head 43a is performed by pushing from behind (the details of the mounting structure of the hardness adjusting knob 44 will be described later). The boss 44 a of the hardness adjusting knob 44 is loosely fitted in the through hole 35 of the outer shell 10.

  Since the boss portion 44a of the hardness adjusting knob 44 is fitted in the through hole 35 of the outer shell 10, even if the engaging portion 36 is detached from the case 17, the backrest 3 is removed from the back support unit 13. There is no. Instead of fitting the boss portion 44 a of the hardness adjusting knob 48 into the through hole 35, another member through which the rod 43 passes may be fitted into the through hole 35.

  In the present embodiment, the hardness adjusting knob 44 is formed in a substantially oval shape that is long in the direction orthogonal to the hardness adjusting knob 44 while being rounded as a whole. FIG. 6 shows a state where the initial elastic force of the compression coil spring 40 is close to the weakest state. When the hardness adjusting knob 44 is rotated from this state, the front spring receiver 41 is pulled backward. It moves and the initial elastic force becomes stronger. Further, when the initial elastic force is set to the weakest state, the spacer 48 becomes a stopper, and the forward movement of the front spring receiver 41 is prevented.

  When a seated person leans against the backrest 3, the rear spring support 42 is pushed forward due to the difference between the tilting fulcrum of the backrest unit 13 and the tilting fulcrum of the spring unit 14, and thereby the backrest 3. Tilts backward while compressing and deforming the compression coil spring 40. When the backrest 3 is tilted backward, the spring unit 14 is also tilted backward, and the rear spring receiver 42 slides relative to the adjustment rod 43.

(4) Details of Hardness Adjustment Knob Next, details of the mounting structure of the hardness adjustment knob 44 will be described with reference to FIG. 12A is an enlarged view of the same portion as FIG. 6, FIG. 12B is a cross-sectional view taken along the line BB in FIG. 12A, and FIG. 12C is a cross-sectional view taken along the line CC in FIG.

As described above, the hardness adjusting knob 44 includes the front member 50 having the cylindrical boss portion 44a and the rear member 51 fitted to the front member 50, both of which are formed inside the boss portion 44a. It is fixed with a countersunk screw 52 inserted from above. And by making the cross section inside the boss | hub part 44a into a substantially hexagon, while holding | maintaining the head 43a of the adjustment rod 43 so that relative rotation is impossible, the latching nail | claw 53 which has a mountain-shaped protrusion in the location of two opposing sides is provided. by forming, Ru Ketei Installing the adjusting rod 43 by insertion from the rear (also can be removed venting and applying a force to some extent.).

  The front end of the locking claw 53 is located behind the opening surface of the boss portion 44a. A ring 54 circumscribing the inner surface of the boss portion 44 a is fitted into the neck portion of the adjustment rod 43. Due to the presence of the ring 54, the hardness adjusting knob 44 is held in a state free from backlash while using a normal bolt as the adjusting rod 43 and being easy to attach and detach.

(5) Details of Lock Mechanism Next, details of the lock mechanism by the lock lever 8 will be described with reference to FIGS. 13 is a plan view, FIG. 14A is a cross-sectional view taken along the line XIVA-XIVA in FIG. 13, FIG. 13B is a cross-sectional view taken along the XIVB-XIVB line in FIG. 13, and FIG. -XVA sectional view, (B) is a BB sectional view of (A).

  A rotation shaft 56 is attached to the lock lever 8 so as not to be relatively rotatable, and a pair of left and right stoppers 26 are attached to the rotation shaft 56 so as to be relatively non-rotatable due to engagement of fin pieces 57 crushed on the rotation shaft 56. It has been.

  The stopper 26 is supported by a receiving member 27. The receiving member 27 is made of a synthetic resin, and has an engaging portion 27a that is concave and convex in a side view and can be bent and deformed in the vertical direction, while the stopper 26 is fitted to the engaging portion 27a of the receiving member 27. The uneven portion 26 a is formed, and the standing state (locked posture) is maintained by the engagement of the uneven portion 26 a and the engaging portion 36. When a certain amount of force is applied from the state of FIG. 14A to rotate the rotation shaft 56 counterclockwise, the front surface of the stopper 26 overlaps the upper surface of the receiving member 27, and the engaging portion 36 and the uneven portion 26a mesh with each other. The unlocked state is maintained.

  The rotating shaft 56 of the lock lever 8 needs to be rotatably supported by the seat receiving base 6 and held so as not to be detached. The rotating shaft 56 is rotatably fitted in a hole formed in one side plate (the side plate on the left side in FIG. 13) of the seat receiving base 6, and the tip is formed inside the seat receiving base 6. The rib 58 is rotatably fitted in a recess 59 (which may be a through hole).

  The tip 56a of the rotating shaft 56 is slightly exposed from the rib 58 located inside the seat receiving base 6, and a snap ring 60 is fitted into the annular groove formed in the tip 56a as a retaining means. Yes. Since the tip of the rotating shaft 56 is hidden inside the seat receiving base, it is excellent in aesthetics.

  The lock lever 8 is composed of an inner member 61 having a boss portion 61a and an outer member 62 fitted thereto, and both are fixed by screws 63. The cylindrical portion 62a formed on the outer member 62 is replaced with the boss portion. It extends to the vicinity of the opening edge of 61a.

  Then, as a method of attaching the lock lever 8 to the rotating shaft 56, the fin piece 64 is formed by crushing on the rotating shaft 56 so as to decrease in height as it goes to the tip, while formed on the outer member 62. A long groove 65 in which the fin piece 64 of the rotating shaft 56 is slidably fitted is formed in the cylindrical portion 62a. Further, the fin piece 64 gets over the inner periphery of the boss portion 61a of the inner member 61 by elastic deformation. The engaging claw portion 66 is formed.

  Since the rotary shaft 56 is held on the outer member 62 so as not to be rattled, and the fin piece 64 only gets over the claw portion 66 at the time of attachment, the attachment can be reliably performed with a light force.

(6). Others The present invention can be embodied in various ways other than the above embodiment. For example, the shape of the back support unit can be arbitrarily changed based on a request for design or the like. As a mode in which a portion of the outer shell below the mounting hole is supported by the back support unit, only the left and right intermediate portions may be supported by the back support unit.

Furthermore, the present invention is to Rukoto applied to chair synchro structure seat to retraction and rear tilt in conjunction with the tilting after the backrest is also possible. Ru also der be provided three or more spaced to the left and right and the strut portion and the outer shell mounting holes of the back rest unit.

Furthermore, it is possible to provide three or more types of fitting means, and the arrangement of the male fitting portion and the female fitting portion can be arbitrarily set (for example, a male fitting portion is formed on the outer shell). it is also possible to form a female fitting portion to the back rest unit in.).

It is a front view of the chair of the chair which concerns on embodiment of this invention. (A) is a plan view of the chair, and (B) is a left side view. It is a perspective view of the outer shell 10 of a backrest. It is a separation perspective view of a member. It is a top view in the state where a seat was omitted. 2 is a longitudinal side view showing a relationship among a back support unit, a spring unit, and an outer shell 10. FIG. It is a separate front view of a back support unit and a backrest. FIG. 11 is a partially cutaway front view with the backrest attached to the back support unit and a view taken along the line VIIIA-VIIIA in FIG. 10. It is a bottom view of a backrest. (A) is a sectional view taken along line XA-XA in FIG. 8, and (B) is a sectional view taken along line BB in (A). (A) is a cross-sectional view in the middle of attaching the backrest as viewed from the XIA-XIA view of FIG. 7, (B) (C) is a cross-sectional view of the XIB-XIB view of FIG. 8 with the backrest attached. XIC-XIC sectional view, (D) is a rear view of the back support unit 13. It is sectional drawing which shows the attachment structure of the knob for hardness adjustment. It is a top view which shows a locking mechanism. (A) is a cross-sectional view taken along the line XIVA-XIVA in FIG. 13, (B) is a cross-sectional view taken along the line XIVB-XIVB in FIG. (A) is a cross-sectional view taken along the line XVA-XVA in FIG. 13, and (B) is a cross-sectional view taken along the line BB in (A).

2 seat 3 backrest 6 seat base 10 outer shell as an example of main support 13 back support unit 14 spring unit
17 Case 18 struts 29 first constituting the male engaging portion of the horizontal axis portion 18c first fitting means that make up the male engaging portion of the back receiving rod member 18a second engagement means for constituting the unit clamping portion constituting the female engaging portion of the mounting hole 33 and the second fitting means constituting the female fitting portion of the fitting means
36 engaging part
36a Step
40 Compression coil spring

Claims (2)

A seat, a backrest having a main support having a strength to support a backrest load of a seated person, and a back support unit to which the backrest is attached, and the main support is provided to the main support of the backrest and the backrest unit. There is provided an attachment means that fits each other by moving from substantially upward to downward or substantially from rear to forward and holds both in a relatively unmovable relative forward and backward direction,
Furthermore, the attachment means includes at least two types of fitting means, ie, at least a first fitting means and a second fitting means, and these fitting means cannot move relative to each other in the front-rear direction when they are fitted to each other. Consists of a pair of a male fitting part and a female fitting part ,
The first fitting means and the second fitting means are provided such that the vertical position and the left and right position are shifted from each other, and the male fitting portion and the female fitting portion of the first fitting means The fitting length is longer than the fitting length between the male fitting portion and the female fitting portion in the second fitting means, and the male fitting portion and the female shape of the first fitting means. When the main support is moved in a state where the fitting portion is fitted, the male fitting portion and the female fitting portion of the second fitting means are set so as to fit each other.
The structure
The back support unit is attached to the seat support base so as to tilt backward against the spring means, and a pair of left and right support posts which are male fitting portions of the first fitting means are attached to the back support unit. While the part is arranged in a state of being divided left and right in front view,
The main support is formed in a shell shape by a synthetic resin, and a mounting hole of a downward opening in which the column portion is fitted as a female fitting portion of the first fitting means is formed at a lower end portion of the main support. Formed,
Further, a pinching portion that opens downward in a side view is formed as a female fitting portion of the second fitting means at a portion below the lower end of the mounting hole in the front portion of the main support. The back support unit is provided with a horizontal shaft portion, as a male fitting portion of the second fitting means, into which the clamping portion is fitted from above by deformation against elasticity.
Chair with backrest. The spring means is a compression coil spring, and the back support unit includes a case having a substantially downward opening that covers the coil spring, and the horizontal shaft portion protrudes from the rear of the case to the left and right, and the support column The part is formed by bending, and the support part is mounted with a pin-shaped protective member made of synthetic resin that fits inside the mounting hole,
As the engaging means for holding the main support in a state where it does not move upward from the back support unit at the lower end portion of the main support and on the front surface portion, a step portion that is hooked from below is formed on the rear lower end edge of the case. When the first fitting means and the second fitting means are fitted to each other, the step portion is set so as to be hooked from below at the lower end edge of the rear portion of the case by elastic deformation of the main support.
A chair with a backrest according to claim 1.

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